I frequently tried to produce imitation, but almost wholly without success. For example, when he was striving to accomplish something with his blocks I would intervene and show him, by example, how, as I thought, it might be done, but these suggestions were invariably, so far as I remember or have recorded, received with indifference or protest. He liked to puzzle it out quietly for himself, and to be shown how to do a thing often seemed to destroy his interest in it. Yet he would profit by observation of others in his own fashion, and I sometimes detected him making use of ideas to which he seemed to pay no attention when they were first presented. In short, he showed that aversion, which minds of a pondering, constructive turn perhaps always show, to anything which suddenly and crudely broke in upon his system of thought. At the same time that he was so backward in the ordinary curriculum of childhood, he showed in other ways, which it is perhaps unnecessary to describe, that comparison and reflection were well developed. This preoccupation with private experiment and reflection, and reluctance to learn from others, were undoubtedly a cause of his slow development, particularly in speech, his natural aptitude for which appeared in a good enunciation and a marked volubility as soon as he really began to talk. Imitation came all at once: he seemed to perceive quite suddenly that this was a short cut to many things, and took it up, not in a merely mechanical or suggestive way, but consciously, intelligently, as a means to an end. The imitative act, however, was often an end in itself, an interesting exercise of his constructive faculties, pursued at first without much regard to anything beyond. This was the case with the utterance of words, and, later, with spelling, with each of which he became fascinated for its own sake and regardless of its use as a means of communication. In a second child, M., a girl, I was able to observe the working of a mind of a different sort, and of a much more common type as regards imitation. When two months and seven days old she was observed to make sounds in reply to her mother when coaxed with a certain pitch and inflection of voice. These sounds were clearly imitative, since they were seldom made at other times, but not mechanically so. They were produced with every appearance of mental effort and of delight in its success. Only vocal imitations, of this rudimentary sort, were observed until eight months was nearly reached, when the first manual imitation, striking a button-hook upon the back of a chair, was noticed. This action had been performed experimentally before, and the imitation was merely a repetition suggested by seeing her mother do it, or perhaps by hearing the sound. After this the development of imitative activity proceeded much in the usual way, which has often been described.